Crossing gate lock



Sept. 16, 1941. MOD DILLEY 2,255,878

CROSSING GATE LOCK Filed Nov. 25, 1958 5 Sheets-Sheet 1 3- ll lo :1, 55

47 g g L 6 0 0 o oo I oo 18 50 g /'Z5' v 3 immmm 4452 50 rfleys Sept. 16, 1941. 2,255,878

, M. McD. DILLEY CROSSING GATE LOCK Filed Nov. 25, 1958 3 Sheets-Sheet 2 lIllIIIIIII/IA Sept. 16, MCD' DILLEY I I CROSSING GATE LOCK Filed Nov. 25, 1938 3 Sheets-Sheet Z I 7714277207, Morris W52 D/l/{y Patented Sept. 16, 1941 UNITED STATES PATENT I OFFICE CROSSING GATE LOCK ville, Ky.

Application November 25, 1938, Serial No. 242,195

Claims.

This invention relates to means for retaining a trafiic crossing gate positively in either its operated or inoperative positions, these positions being hereinafter referred to as a lowered or horizontal position and a clear or up position. An important object of the invention is to provide means which will permit the gate to travel on to the desired selected position, but after reaching that position, will prevent its return until the return action is indicated. In the form herein shown, the invention is applied to a light duty type power gate which may be applied to new or existing warning sign poles or the like, although the invention is equally as well adapted for use in heavy duty type gates of other constructions.

A further feature of the invention is that upon power failure the automatic holding means may be released to permit the gate arm to assume either the clear or down positions depending upon the arrangement of counterweights so as to meet the requirements of the particular installation as to whether or not the crossing is to be kept clear or closed in the event of such power failure.

These and many other objects and advantages H by means of bolts tomarily (although not necessarily so) with the usual flasher lamps I21; and Hi) together with the usual visual warnings as to Railroad crossing and Stop on red signal.

The box I0 is adjustably mounted on the post l2 extending through knockouts in the box. This permits adjusting the control box Ill at any elevation or angular position around the post H as may be desired or required for the particular crossing.

A single arm I3 is carried by a yoke M which hangs downwardly from a transverse axle I'5 extending through the box In. The yoke i4 is so formed as to have its mass suspended below the axle H5. The yoke l4 curves around upwardly to carry weights it normally above the level of the arm !3 when the arm is in the lowered position. The travel of the gate is indicated in Fig. 1 from the dash lines of the up or clear position down to the solid lines for the closed or lowered position. This peculiar mounting of the arm I3 not only gives an easier control of the movementof the arm l3 but also provides clearance for the various signals on the post ll when the arm is in the up position.

The axle l5 carries a gear segment ll which meshes with a vertically disposed rack [8 directly connected to a piston rod I9 carried by a cylinder 20 to travel vertically. The cylinder 28} carries a piston 2|, Fig. 3, to which the rod l9 is connected. The cylinder 20 is closed at both Fig. 3, a detail in vertical section on the line Y 1 3-3 in Fig. 2;

Fig. 4, a top plan View on a still further enlarged scale of the automatic holding valve;

Fig. 5, an end elevation on a reduced scale;

' Fig. 6, a central vertical section on the line 5-6 in Fig. 5;

Fig. 7, a vertical section on the line l'! in Fig. 5 on enlarged scale;

Fig. 8, a central longitudinal vertical section through the valve similar to that shown in Fig. 6 but having a modified form of release; and

Fig. 9, a schematic wiring diagram.

Like characters of reference indicate like parts throughout the several views in the drawings.

In the present form of the invention, the entire control is carried within a box H] which may be mounted on the ordinary signal post H customarily employed at a highway crossing over a railway. The invention may be. employed cusends. The gate is actuated by travel of the piston 2| within the cylinder 20 by pumping oil into the cylinder to shift the piston accordingly.

To supply the oil under pressure, a pump 22, generally of the gear type, in any event being of a rotary construction, is driven by an electric motor 23, here shown as in direct connection through the shaft 24. Between the pump 22 and the cylinder 20 is located the looking valve 25.

This valve has a major horizontally disposed cylinder 26 within which are mounted a pair of pistons 21 and 28 in spaced apart relation on a common piston rod 29. The pistons 21 and 28 in the present form consist each of a pair of oppositely disposed leather cups. There is no external extension of the rod 29 from the cylinder 26 and the movement of the pistons is created solely by variations of pressure on their faces. A longitudinal passageway 30 extends along one side of the valve 25 to have end passageways 3| and 32 respectively continue from the passageway 38 across the ends of the valve and discharge into the respective ends of the cylinder 25. This passageway 30 is intercepted by a pair of spaced apart ball check valves 33 and 34 respectively so that fluid flow through the passageway from either end of the cylinder 26 is arrested selectively by these valves. That part of the passageway 3|] which lies between the two valves 33 and 34 has a transverse passageway 35 leading therefrom to discharge into the cylinder 26 through the opening 36.

The pump 22 has a discharge pipe 31.1ead1ng to the valve 25 and discharging into the passageway 32 through the nipple 38, Fig. 7. Assuming that the gate arm I3 is to be lowered and the motor 23 is in operation and driving the pump 22, oil will be forced through the pipe 31 into the passageway 32. The only escape from that passageway by reason of the presence of the check valve 34 is through the opening into the end of the cylinder 26, Fig. 6. The oil flowing into the cylinder 26 will push the piston 28 back in the cylinder to its limit of travel which is reached when the piston 21 strikes the opposite cylinder end, as indicated in Fig. 6. The cylinder 26 is provided with one or more openings 39 through the cylinder wall ahead of the piston 28 so that the oil may escape from the cylinder as it ispumped therein into an upperpassageway 40 from which a pipe 4| leads to the top of the cylinder 20. Thus the oil is carried from the pump 22 through the valve cylinder 26 and into the top of the cylinder 20 to force the piston 2| downwardly and thus lower the gate I3.

While this down travel of the piston 2| has been taking place, the oil in the lower part of the cylinder 26 under the piston 2| is forced outwardly through the pipe 42 leading from the bottom of the cylinder and connecting with the passageway 43 at the top of the valve 25. This passageway 43 opens into the cylinder 26 between the pistons 21 and 28 through one or more openings 44. The oil entering the cylinder 26 from these openings 44 flows between the pistons 21 and 28 and leaves the cylinder 26 through the opening 36 which is never covered by either piston. This discharging oil comes into the central part of the passageway 36 between the check valves 33 and 34. Since the pump is supplying pressure in that part of the passageway 30 which connects with the passageway 32, the valve 34 will remain seated, but the valve 33 may lift and allow the discharge oil to flow therepast into the other partof the passageway 38 and leave that passageway through the opening 45 from which the pipe 46 leads back to the pump 22 to constitutethe intake of the pump in this sequence of operations. In other words, there is a closed circult of the oil which is used as the medium for supplying pressure to shift the'piston 2|.

When the piston 2| reaches its lower limit of travel, which is that position wherein the gate arm I3 is horizontally disposed, a lower limit switch 41, Fig. 2, will be opened by any suitable means such as a finger 48 on the rack I8 and thereby open the electrical circuit which includes the motor 23 and thus stop the pump 22. When the pump has stopped, there is a residual pressure'left in the cylinder 26 on the upper side of the piston 2 I. and this pressure is maintained by reason of the fact that there can be no back flow of oil through the valve 25 by reason of the inder 26, and further that once pressure is applied to the cylinder, that pressure cannot be relieved until the pistons 21, 28 have been shifted to the opposite end of the cylinder 26 so as to interconnect that pressure side of the cylinder with the outlet opening 36.

Thus it is to be seen that by interposing this control valve 25 between the pump and the cylinder, a piston check is introduced to maintain the pressure in the cylinder irrespective of pump leakage or the like. The gate cannot be pushed upwardly without release of this pressure. To permit adjustment of the gate or checking of it, there is interposed a by-pass between the passageways 46 and 43 intercepted by the valve 50, Fig. 6, which in this form is manually operated. By opening the valve 50 through the external handle 5|, there is a direct interconnection made between the passageways 4B and 43 which relieves the pressure in the cylinder while allowing the oil to flow from the pressure side from the passageway 46 past the valve 50, through the passageway 43 and into the cylinder 26 and out through the opening 36.

This control of the by-pass between the passageways 4B and 43 may be electrically operated by means of a solenoid 52 normally included in the operating circuit to hold a valve 53 in a closed position, Fig. 8. The valve in this case would be so constructed as to normally open by any such means as a spring 54 when the current fails so as to permit the gate arm I3 to swing to either an up or a down position depending upon the amount of weights I6 applied to the yoke I4. That is, where the arm I3 is not balanced by weights I6, the gate I3 would drop to a closed.

I3 is overbalanced by the weights I6, it would lift to its open or up position upon current failure. I

One sequence of operations has been described above. In order to lift the gate, regardless of whether the weights I6 fully balance or not the arm I3, the motor 23 is reversed in direction of travel so as to reverse the direction of output of oil from the pump 22. In this case, the discharge from the pump 22 would be through the pipe 46 into thepassageway 3| so as to initially drive the pistons 21 and 28 toward the opposite end of the cylinder 26 and thereby provide a path for the oil to flow from the passageway'3l to the openings 44 and out through'the pipe 42 into the bottom of the cylinder 2|]. At the same time the openings 39 are then between the pistons 21 and 28 so as to open up the discharge passage for the oil to the opening 36 into the passageway 30 past the check valve 34' and back to the pump 22 through the pipe 31.

When the rack I8 reaches its upper limit of travel, it will open the limit switch 55 and thereby interrupt the circuit to the motor 23. Preferably the motor 23 is not only wound to be reversible but is also wound to give a higher speed on the reverse travel than it has on the initial down travel of the gate. The electrical circuit is indicated by the diagram as shown in Fig. 9, wherein wires 60, 6| lead from any suitable source of operating current, generally ten volts, direct current. Across these wires would be connected the solenoid winding 52 which normally holds the valve 53 in the closed position. A track relay 62 upon being energized pulls the switch 63 into the closed position and current then flows through the lower limit switch 41 normally in the closed position, assuming that the gate is in its raised position. From the closed switch 41, the current flows through the conductor 65, through the relay winding 66 and back through the conductor 61 to the wire 6!. The relay B9 closes switches 68, 59 which interconnectthe common conductor 10 leading from the wire 60 with the two motor leads H and 12. The motor 23is constantly connected with the wire 61. The motor 23 then remains in the circuit until the limit switch 41 is opened by the rack I8.

When the train leaves a block protecting the crossing, the relay 62 is then operated in the usual manner (by track circuits not shown) to cause the switch 63 to then interconnect the wire 60 with the wire 64 leading to the upper limit switch 55 which is closed after the rack I8 starts on its down travel in the initial operation above described. From the switch 55 leads conductor I3 to the relay 14 which has a return wire 15 connected with the wire 6|. The relay 14 will close the switches 16 and 11 to interconnect the wire 60 with the motor leads [2 and l8'to give the reversing action. The motor 23 remains in this reverse circuit until the switch 55 is opened by the rack H3 at its upper limit of travel. Thus the motor 23 is again stopped and remains in that condition until the track relay 62 is again operated to lower the gate as above described.

While I have herein shown and described my invention in the one particular form, it is obvious that structural details may be varied without departing from the spirit of the invention, particularly in the type of pump employed and the exact structural details of the control valve, and I, therefore, do not desire to be limited to that precise form beyond the limitations as may be imposed by the following claims.

I claim:

1. In a crossing gate control, the combination with an operating cylinder, a piston in the cylinder, a pump having a reversible intake and discharge flow for supplying fluid to the cylinder to actuate the piston, of an interlocking valve between the pump and the cylinder, said valve having a cylinder, a piston in the cylinder with a fluid receiving space between ends of the piston, a passageway leading from each end of the valve cylinder to the discharge and intake of said pump, a discharge passageway leading from a port in the valve cylinder located to be always in communication with said piston space, said discharge passageway connecting with each of said valve cylinder end passageways, a check valve between said discharge passageway and each of the other passageways arranged to prevent flow from those passageways into the discharge passageway and permitting reverse flow, a passageway leading from a port in the valve cylinder to one end zone of the operating cylinder, another passageway leading from another port in the valve cylinder to the other end zone of the operating cylinder, said last ports being located to have said valve piston by travel thereof alternately include one of those ports and said discharge port in said piston space to control flow therebetween.

2. In a crossing gate control, the combination with an operating cylinder, a piston in the cylinder, a pump having a reversible intake and discharge flow for supplying fluid to the cylinder to actuate the piston, of an interlocking valve between the pump and the cylinder, said valve having a cylinder, a piston in the cylinder with a fluid receiving space between ends of the piston, a passageway leading from each end of the F valve cylinder to the discharge andintake of. said pump, a discharge passageway leading from a port in the valve cylinder located: to be always in. communication with said piston space, said discharge passageway connecting; with each of said valve cylinder end passageways, a check valve between said discharge passageway and each of the other passageways arranged. to prevent flow from those passageways into the discharge passageway and permitting reverse flow, a passageway leading from a port in the valve cylinder to one end zone of the operating cylin der, another passageway leading from another port in the valve cylinder to the other end zone of the operating cylinder, said last ports being located to have said valve piston by travel thereof alternately include one of those ports and said discharge port in said piston space to control flow therebetween, and a valve controlled by-pass between said passageways leading to the operating cylinder.

3. In a crossing gate control, the combination with an operating cylinder, a piston in the cylinder, a pump having a reversible intake and discharge flow for supplying fluid to the cylinder to actuate the piston, of an interlocking valve between the pump and the cylinder, said valve having a cylinder, a piston in the cylinder with a fluid receiving space between ends of the piston, a passageway leading from each end of the valve cylinder to the discharge and intake of said pump, a discharge passageway leading from a port in the valve cylinder located to be always in communication with said piston space, said discharge passageway connecting with each of said valve cylinder end passageways, a check valve between said discharge passageway and each of the other passageways arranged to prevent flow from those passageways into the discharge passageway and permitting reverse flow, a passageway leading from a port in the valve cylinder to one end zone of the operating cylinder, another passageway leading from another port in the valve cylinder to the other end zone of the operating cylinder, said last ports being located to have said valve piston by travel thereof alternately include one of those ports and said discharge port in said piston space to control flow therebetween, and a valve controlled by-pass between said passageways leading to the operating cylinder, an operating electric circuit, and a solenoid controlling said by-pass valve normally energized by said circuit to hold said valve closed.

4. In a crossing gate control, a cylinder, a gate operating piston in the cylinder, a pump for supplying fluid to the cylinder under pressure, said pump being reversible in action, a gate position maintenance valve between the cylinder and the pump interconnected with intake and discharge fluid conductors to said pump, fluid conductors leading from the valve to connect with opposite ends of the cylinder, a piston in the valve initially shiftable by fluid delivered from the pump, said shifting causing one of said cylinder conductors to be interconnected through the valve with the discharge conductor of the pump to cause shifting of the gate operating piston, and said valve piston shifting also setting up a flow connection between the other of said cylinder conductors to said pump intake conductor, said pump discharge and intake conductors having an interconnecting passageway with a port in said valve controlled by said valve piston for selective communication with either of said cylinder conductors, and a pairof spaced check valves in said passageway arranged to have said port discharge therebetween. V

5. A crossing gate lock valve-consisting of a cylinder, a conductor interconnecting each end of the cylinder and an intermediate port in the cylinder, a valve in said conductor on each side of'said port arranged to close upon pressure in the conductor and to open upon pressure therebetween communicated through said port, said cylinder having an additional port toward each 10 end, a conductor having a pairof discharge ports between said additional ports, a valve intercepting said last conductor between said discharge ports and said additional ports, and a piston in the cylinder having a recessed central portion,

always in communication with said intermediate port, said piston being proportioned to travel to selectively uncover one of said additional ports within'said recess and to uncover the other of the additional ports outside of the piston, said first conductor having an inlet and an outlet port each between a valve in the conductor and the conductor connection cylinder end.

MORRIS McD. DILLEY. 

